Research at the Koch Institute combines a wide spectrum of innovafive programs designed to understand tumor development and develop new treatments and diagnostic strategies. Many of the approaches taken, in disciplines ranging from molecular and cell biological to analysis of mouse models and nanotechnology, rely on imaging. In 2005, using non-renewable institufional funds, the Koch Institute established a Microscopy Core Facility that makes centralized, state-of-the art imaging equipment available to Center investigators and other NCI-funded investigators at MIT. CCSG funds are requested to provide confinuing support for this Core. The Microscopy Core curl-ently offers a wide range of imaging platforms including standard light and epifiuoresence to digital deconvolution, spinning disk confocal microscopy, and systems for spectral Karyotyping (SKY) and laser capture microdissection. The Core is run by a highly qualifled Core Manager, who has extensive expertise in a broad range of microscopy platforms and applications including electron microscopy and live cell/organotypic fluorescent 4D imaging. The Core Manager oversees all instrumentafion, provides state-of-the-art training to Center members in both sample preparation and use of the Core's equipment and also conducts specific microscopy techniques for Kl users on a fee-for-service basis. She also collaborates with the Applied Therapeufics & Whole Animal Imaging Core Facility, providing technical support and user training for the whole-animal imaging instrumentafion including luminescence/fluorescence detection and microCT applicafions. The Microscopy Core has proven invaluable to a large fraction of the Kl faculty by allowing them to execute microscopy-dependent projects that were previously impossible given the expense of acquiring and maintaining imaging equipment. In the upcoming grant period, the Kl will confinue to add new equipment to both the Microscopy and Applied Therapeutics & Whole Animal Imaging Core Facilities to further expanding their imaging capabilities. This expansion, as well as high demand for existing services, requires addition of a technical assistant to the Microscopy Core Facility staff. User chargebacks provide partial support the Microscopy Core, but the operational costs are currently undenA/ritten by Institutional funds that will expire in June 2009. Thus, the requested CCSG support is critical for the confinued success of this essenfial Microscopy Core.